1. Technical Field
The field relates to sound reproduction and more particularly waveguides for collecting and directing sound from multiple sources at high intensities.
2. Description of the Problem
In U.S. Pat. No. 7,837,006 Graber described a sound field blending and projection system which combined inputs from a plurality of loudspeakers arranged in a circular or radial array. The loudspeakers were horn loaded with the effective mouths of the horns being differentially located for different frequencies. The horn mouth at lower frequencies was a blended mouth for what was in effect a multi-throated horn which exhibited a fold for low frequencies. Higher frequencies were directed inwardly against a spike or cone like reflector located at the center of the circle. The reflector was oriented to merge the higher frequency sound waves in a beam and to reflect the beam along a radiant axis at a right angle to the plane of the circle. For lower frequency sound the central spike or cone was largely ineffective with low frequency sound directed along the same radiant axis as for the higher frequencies by the blended horn mouth and horn fold.
Compression plugs are well known devices for increasing transducer efficiency and numerous references relate to their use with single transducers coupled with a horn.